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Ultrasound and Vascular Lab

Ultrasound has been used as a noninvasive diagnostic medical test to assess soft tissue structures for over 40 years. Ultrasound uses sound waves with sophisticated computers to produce multiple images, or pictures, of the inside of the body. OHSU Diagnostic Imaging Services highest priority is to provide the best positive patient experience. Please feel free to call with questions regarding your appointment: 503-418-0990.

What is an Ultrasound?

Ultrasound exams use a transducer that sends high frequency ultrasonic sound waves to look at the internal soft tissues organs. When the transducer is placed against the skin, the ultrasonic sound waves move through the skin and other body tissues to the organs and structures. The sound waves bounce off the organs like an echo and return the waves back to the transducer. The transducer picks up the reflected waves that are converted by a computer into an electronic picture of the organs or tissues. Different types of body tissues affect the speed at which sound waves travel. Sound travels the fastest through bone tissue and moves slowly through air. The speed and amount of the sound waves that are returned are translated by the transducer as different types of tissue. No radiation is used in ultrasound so the risks to patients are negligible.

What is a Vascular Ultrasound?

Blood flow can be assessed by using an additional mode of ultrasound technology during an ultrasound procedure. An ultrasound transducer that contains a Doppler probe evaluates the velocity and direction of blood flow in the vessel by making the sound waves audible. The degree of loudness of the audible sound waves indicates the rate of blood flow within a blood vessel. Absence or faintness of these sounds may indicate an obstruction (blockage) of blood flow.

Blood flow can be assessed by using an additional mode of ultrasound technology during an ultrasound procedure. An ultrasound transducer that contains a Doppler probe evaluates the velocity and direction of blood flow in the vessel by making the sound waves audible. The degree of loudness of the audible sound waves indicates the rate of blood flow within a blood vessel. Absence or faintness of these sounds may indicate an obstruction (blockage) of blood flow. To assess blood flow in the limbs, segmental blood pressures may be performed.

Ultrasounds are used to view internal organs in "real time," like a live TV broadcast to assess blood flow through various vessels. Ultrasound procedures are often used to examine many parts of the body such as the abdomen, breasts, female pelvis, prostate, scrotum, thyroid and parathyroid glands, and the vascular system. During pregnancy, ultrasounds are performed to evaluate the development of the fetus. Technological advancements in the field of ultrasound now include images that can be made in a three-dimensional view (3-D) and/or four dimensional (4-D) view. The added dimension of the 4-D is motion, so that it is a 3-D view with movement.

OHSU's Ultrasound department is accredited by the American College of Radiology (ACR). OHSU’s Vascular Lab department is accredited by the Intersocietal Accreditation Commission (IAC). This designation is gained by seeking and earning accreditation through the acquisition of clinical images, submission of relevant physician reports corresponding to clinical images submitted, and quality control documentation.1

Ultrasound and Pregnancy

Diagnostic Radiology works closely with departments such as Gynecology and Obstetrics and Perinatology for your Pregnancy Care. A screening ultrasound is sometimes done during the course of a pregnancy to monitor normal fetal growth and verify the due date. Ultrasounds may be performed at various times throughout pregnancy for different reasons:

First trimester

To establish the dates of a pregnancy

To determine the number of fetuses and identify placental structures

To diagnose an ectopic pregnancy or miscarriage

To examine the uterus and other pelvic anatomy

In some cases to detect fetal abnormalities

Mid-trimester: (sometimes called the 18 to 20 week scan)

To confirm pregnancy dates

To determine the number of fetuses and examine the placental structures

To assist in prenatal tests such as an amniocentesis

To examine the fetal anatomy for presence of abnormalities

To check the amount of amniotic fluid

To examine blood flow patterns

To observe fetal behavior and activity

To examine the placenta

To measure the length of the cervix

To monitor fetal growth

Third trimester:

To monitor fetal growth

To check the amount of amniotic fluid

As part the biophysical profile

To determine the position of a fetus

To assess the placenta

What should I expect during my visit?

Your appointment is unique to you. If you were not provided with a specific appointment date and time by your provider, please call us to schedule your Ultrasound or Vascular exam. When you call to schedule your appointment, a scheduling professional will provide you with any preparation instructions specific to your exam. You can also obtain preparation instructions via e-mail by signing up for MyChart during your clinic visit.

On the day of your US exam, a technologist may ask you to remove clothing or other objects that may interfere with the procedure. If you are asked to remove any clothing, you will be given a gown to wear. A gel-like substance will be smeared on the area of the body to undergo the ultrasound (the gel acts as a conductor). A transducer is used by the ultrasound technologist by moving it around in the gel to view varies structures on the screen. There are no confirmed adverse biological effects on patients or instrument operators caused by exposures to ultrasound.